Cancer constitutes a significant public health concern, and addressing the challenge of cancer holds paramount importance and requires immediate attention. Epigenetic alterations, encompassing DNA methylation, have emerged as pivotal contributors to the development of diverse cancer types. These modifications exert their influence by modulating chromatin structure, gene expression patterns and other nuclear processes, thereby influencing cancer pathogenesis. Over the last two decades, an increasing body of evidence has established the involvement of DNA methyltransferase 1 (DNMT1) in various aspects of cancer development, including tumorigenesis, aggressiveness and treatment response. Furthermore, non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are increasingly recognised as significant modulators in diverse biological processes, encompassing metastasis, apoptosis, cell proliferation and differentiation. Several recent studies have elucidated the intricate relationship between epigenetic machinery, specifically DNMT1, and the expression of ncRNAs in the context of cancer. In this review, we provide a comprehensive overview of the interaction between DNMT1 and ncRNAs in cancer pathogenesis. Furthermore, we discuss the important role of the ncRNAs-DNMT1 axis in cancer stem cells and cancer therapy resistance as critical issues in cancer therapy. Finally, we demonstrate that herbal medicine and synthetic RNA molecules regulate DNMT1 activity and hold great promise in cancer treatment.